BlueRock Diamonds PLC (LON:BRD) told investors that sales from the Kareevlei diamond mine rose 71% to 5,805 carats for 2018.
Production volumes for the full year amounted to 189,990 tonnes, up 24%, whilst the average grade increased by 34% to 3.28 carats per hundred tonnes.
It highlighted that in the fourth quarter, the grade had increased to 4 carats per hundred tonnes, represents a 63% improvement from the average grade for 2017.
"2018 has seen good progress for BlueRock with both production and the recovered grade increasing significantly,” said Adam Waugh, BlueRock chief executive.
“The results from our second kimberlite pipe, KV1, which came on stream in June last year, and from the undiluted levels of our first kimberlite pipe, KV2, have shown a marked increase in grade, which we expect to continue into 2019.
“Our move to 365-day operations is expected to start in February and is expected to give us around 40% additional plant availability. This, coupled with a consistently improving grade profile, makes the outlook for 2019 very encouraging.”
Waugh added: “It is hoped that the operational improvements seen over the last two years and further improvements planned will now translate into generating value for shareholders."